A night at Vienna's Opera Ball

Members of the opening committee perform during the opening ceremony of the traditional Opera Ball in Vienna, Austria. Photo: REUTERS/Leonhard Foeger.

People arrive for the traditional Opera Ball in Vienna, Austria. Photo: REUTERS/Leonhard Foege

Dancers of the Wiener Staatsballett (state ballet) perform during the opening ceremony of the traditional Opera Ball in Vienna, Austria. Photo: REUTERS/Leonhard Foeger

Members of the opening committee prepare for the traditional Opera Ball in Vienna, Austria. Photo: REUTERS/Leonhard Foeger

Members of the opening committee perform during the opening ceremony of the traditional Opera Ball in Vienna, Austria. Photo: REUTERS/Leonhard Foeger

Members of the opening committee perform during the opening ceremony of the traditional Opera Ball in Vienna, Austria. Photo: REUTERS/Leonhard Foeger

Police patrols in front of the opera house during the traditional Opera Ball in Vienna, Austria. Photo: REUTERS/Heinz-Peter Bader

(Reuters)